The present invention pertains to the field of circular knitting machines and, in particular, it pertains to a method for an operative selection of the needles of circular stocking knitting machines, knitting machines and the like for knitting held and dropped stitches.
In general, circular stocking knitting and knitting machines have, around the cylinder which carries the needles for knitting the starting yarns, one or more stations for feeding the yarns and for forming the stitch and a selection unit for operatively controlling the needles. These needles, depending on the knitting process to be carried out, can be controlled, i.e., selected, to individually follow different courses, also called technical paths, of ascending and descending at different levels. Correspondingly, each needle must be able to follow a low course without picking up any yarn fed in, an ascending course that carries it to an intermediate holding level for holding the stitch that was previously knit, and for picking up the yarn, or a higher ascending course in order to reach a level of dropping the respective stitch and picking up new yarn. In other words, depending on the knitting to be carried out, the needles may be induced to follow three technical paths, at a low level, an intermediate level or a high level, respectively. However, with the presence, as currently occurs, of a single unit for selecting the needles in the feed station or in each of the feed stations of a circular stocking knitting machine and the like, the needles can be controlled in each feed station to selectively follow, at the same time, only two of the three technical paths provided for the production of held and dropped stitches.
In fact, a single selection unit does not make it possible to raise the needles that must pass by low without picking up the yarn and to raise the needles that must drop the stitch at the higher level of dropping and picking up new yarn.
Therefore, as in the manufacture of held and dropped stitches, it is evident with the current systems that the selection unit of consecutive feed stations must be engaged with the not indifferent drawback of cutting in half the productive potentials of the circular knitting machines.
The primary object of the present invention is to eliminate this drawback by creating conditions that make possible a production of held and dropped stitches on each feed station of a circular stocking knitting machine, knitting machine and the like for a full exploitation of the productive potential of same, whereas the productive potential was cut in half as explained above in relation to the prior art.
The object of the present invention is accomplished by prearranging two selection units in each feed station of the machine and by using one selection unit to control the needles that must knit a held stitch and the other selection unit to control the needles that must knit a dropped stitch.
The present invention will be better described in the description below and with reference to the attached drawing, in which the sole figure schematically shows the cams and the two selection units corresponding to a feed station of a circular stocking knitting machine, knitting machine or the like.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.